


Sweet Serial Killer

by shootingstarcipher



Category: Gravity Falls
Genre: Angst, Brain Damage, M/M, Masturbation, Romance, Sick!Dipper, Smut, human!bill cipher, terminal illness
Language: English
Status: In-Progress
Published: 2016-08-21
Updated: 2016-10-05
Packaged: 2018-08-10 05:35:00
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Underage
Chapters: 4
Words: 10,804
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7832353
Author URL: https://archiveofourown.org/users/shootingstarcipher/pseuds/shootingstarcipher
Summary: <blockquote class="userstuff">
              <p>The day that Dipper is diagnosed with a rare and fatal disorder is the day that he just happens to run into Bill Cipher, who claims to be suffering from the effects of a head injury after enduring what he considers an act of war committed by none other than Dipper’s great uncle Ford.</p>
            </blockquote>





	1. Escaping Hell

Dipper has decided he hates doctors, that every minute passing by makes him hate them even more, and that sitting there in the unbearably white waiting room of the hospital clinic is pure hell. He’s been there for hours and all he wants to do now is get out. Well, that’s all he’s wanted to do for a while now. In fact, he didn’t want to be there in the first place. It was the doctor at the regular practice who wanted him to go after Grunkle Stan took him there following his first seizure - the first as far as Stan isconcerned, though he knows otherwise.

Stan is sitting beside him now, a look of concern on his face, and Mabel on his left, playfully sticking sequins of various colour on his arm which is splayed across the armrest separating their two chairs. Ford is still at the Mystery Shack, probably in the basement as he always is, and Wendy and Soos are taking care of things there. They don’t have a clue what’s going on. Ford does and he wanted to come to the hospital with them, but Stan wouldn’t allow it (in spite of Dipper’s pleas).

This isn’t the first time they’d come to the hospital. It feels like the millionth. They’ve been there virtually every week for the last couple of months, and each time Dipper was taken into a room with a doctor, interrogated, and then subjected to some fresh kind of torture that was different every time they went. Blood tests, urine tests, skin samples, EEGs… The list goes on. But now he’s finally going to find out what it’s all been in aid of.

Glancing to his right, he sees Grunkle Stan anxiously grip his armrest out of the corner of his eye. This is the first time he’s ever seen him display a nervous behaviour without it involving money or police, and he ends up turning to his sister for comfort, Stan’s obvious and out of place concern only serving to amplify his own. He’s been having seizures for a while now - infrequent seizures - and only thought it odd when Stan witnessed one and suggested there might be something wrong with him. Mabel had been there too and hadn’t understood at the time what was happening to him.

After what feels like an eternity, the door he’s been staring at opens and a doctor in a white lab coat strides towards him, inviting him into the room. Stan goes in with him and tells Mabel to stay put even though Dipper doesn’t want her to. She scowls but does as she’s told anyway, not wanting to make the situation even more difficult than it already is. Once inside, Dipper and Stan sit down next to each other, opposite the doctor. Dipper studies the wall and Stan observes the expression on the doctor’s face, sensing bad news.  
The doctor leans forward, clapping his hands together on the desk in front of him and interlocks his fingers, telling them they have the results of the tests and that they’ve finally been able to come up with a diagnosis. That’s why they bothered coming. This is old news to them and Dipper snorts, anxiety and boredom creeping up on him again. He just wants to know what’s wrong with him so they can hurry up and fix it.

That’s the problem, the doctor tells them. They know what’s wrong with him, but they don’t know how to fix it. There’s no cure and - he lowers his voice, speaking a bit more gently than before - it’s fatal. It’s going to kill him. He won’t live to be in his mid-twenties. Most people with the condition die before their 21st birthday. All Dipper wants to do is run out and burst into tears but he can’t, so he sits there, still and quiet, and listens.

He has an extremely rare condition known as Batten disease. It’s an autosomal recessive neurodegenerative disorder. That’s what the doctor says and that’s what’s written on the leaflet the doctor is sliding over to him - the leaflet he’s determined to throw into the next bin he sets eyes on. How is that going to help anyway? A piece of paper isn’t going to save his life and neither are the doctors, from what it sounds like. He’s going to die in a few years and there’s nothing anyone can do about it. He suddenly feels numb all over and he just wants to go back to the Shack and bury his head in his pillow under the blanket. Maybe he’ll stay like that for a few days before common sense kicks in and he decides to live life to the fullest while he still can.

Leaving the hospital is what he desperately wants but is still so difficult to do. He snatches the leaflet up from the desk, follows Stan out of the room, glances up at Mabel and is suddenly tempted to retreat to the room again and hide away from her. But he doesn’t. Instead, he walks straight over to her and, knowing she’s about to ask whether he’s okay, interrupts her to tell her he doesn’t want to talk about it. The look on his face gives it all away. It doesn’t look good.

As the walk down a series of corridors together, Dipper trailing behind the other two, wanting to be alone, Stan whispers to her about what went on in the doctor’s office. A minute later they pass the hospital gift shop and she drags Stan inside, making her brother wait in the corridor with his back to the shop.

That’s when everything starts to go downhill, even more so than being given a death sentence.

Because he looks up from the floor to find a tall, slender blond boy a couple of years older than he is staggering towards him, almost crashing into him. He expects an apology but never receives one, somehow causing his intrigue to grow. The taller boy gazes down at him and smirks. His lips are thin and he has an eyepatch covering one eye - the eyepatch being obscured by his wavy hair - and the visible eye is pure gold. There’s a large, ugly gash across his forehead that’s difficult to see through his bangs. It’s clearly been stitched up and must have required quite a few stitches. His outfit is strange but striking and gives off an air of elegance, though his white shirt is crumpled and not tucked into the waist of his velvet black trousers and his bow tie and top hat are slightly askew. Everything about him is crooked, from his clothes to his cocky grin and, as Dipper quickly found out, to his personality as well.

“Going home already, Pine Tree?” Dipper flinches at the sickening familiarity of the voice - and that goddamn nickname - and presses himself against the wall, hands clenching into fists as he glares up at the demon in front of him - how he managed to get his hands on a human body so similar to his usual appearance is beyond him, but he has more important matters to consider at the time. “I’ve been stuck here for days,” the demon groans, his frustration evident. “And it’s all because of that damn six-fingered uncle of yours.”

Dipper’s eyes widen and he jerks his head up to stare at him. “What do you mean?” he demands crossly, attempting to mask his confusion with anger. Firstly, the idea that Ford has been aware of Bill Cipher’s presence - and human appearance - and hasn’t yet brought it up to him is preposterous and secondly, Ford would never do anything to hurt someone without just cause, so even if what the demon is saying is true, it probably doesn’t matter because he wouldn’t have hurt him without having a good reason to do so.  
The demon points to his head and sighs heavily in exasperation. “He tried to kill me!” he exclaims suddenly, arms flailing as he loses his balance and ends up grabbing Dipper’s shoulder to keep himself steady. “I’m sick, Pine Tree, and it’s all his fault. He hit me… with something… metal. Now they tell me I’ve got brain damage.” Another sigh, drawn out this time to last a few more seconds. His shoulders drop and he slings an arm around Dipper’s waist, leaning on him for support.

“Get the hell away from me!” Dipper snaps aggressively, shaking him off and ducking away from the demon’s arm as he brings it towards him again in attempt to curl it around him. “You’re right. You are sick. In the head,” he adds, earning an amused chuckle. “And anyway, if you’ve got brain damage, you’re not sick - you’re injured; there’s a difference.”

Bill doesn’t seem to know what to say to that so he keeps his mouth shut, watching the human’s chest rise and fall with every breath in silence. Dipper doesn’t notice at first, but once he does, he cowers under demon’s scrutinising gaze and wishes Mabel and Stan would hurry up. But then his back is against the wall again and the demon’s hands are pressing hard against his chest, imprisoning him. Neither of them speak but his pulse quickens, his heart thudding against his ribcage with more power than he has ever thought possible, warning him to get away.

“Listen, kid,” the demon hisses in his ear, hot breath enveloping the shell of his ear as he claws at the child’s wrists, holding him in place. “I don’t know what’s happening to me and you are the one who’s going to do something about it, alright? I only just finished this body. I’ve spent years trying to get it just right and now I’m not letting it break now, understand? You. Have. To do. Something,” he enunciates, visible eye glowing red as he glowers at him.

For a long, painfully drawn out second, their gazes meet and neither of them looks away. Dipper takes his breathing into his own hands and tries to control it. Anything’s better than those short, sharp intakes of air he’s been struggling through for the last minute or so. “Something,” he repeats, finally taking his eyes off the demon’s face. “Have to do something.”

“Exactly,” Bill grins, his face suddenly brightening up. “You have to take care of me. And I’ll be needing a place to stay - the Mystery Shack will do for that.”

Dipper’s mind goes blank for a short while. He can’t concentrate on anything but the demon’s face, lips curled into an unforgiving grin, his golden eye glistening with mischief. He’s still trapped, pinned against the white painted wall of the hospital, with Bill’s body less than a few inches away from him. He wants to ask why he’s here in the first place, how he had his human body made and why he’s demanding comfort and care from the nephew of his nemesis. But all he does is stand there, body trembling, clutching the leaflet the doctor has given him in his quivering hand.

Bill’s gaze flickers downwards and he catches sight of the flimsy, colourful paper folded up in the human’s hand. “Batten disease,” he reads aloud, focusing on the bold blue writing on the front of the leaflet. Then he raises his head and their eyes meet again, though his grin has disappeared from his face by now, replaced by a solemn expression; the light has died from his visible eye as well, leaving it a dull sort of gold. “So they finally diagnosed you.” His voice, Dipper notes, is neither excited nor concerned. It’s as if all emotion has been drained from it.

They hear footsteps and the demon steps aside, revealing Mabel, who is bounding towards them with a pale blue envelope in her hand and white-furred teddy bear tucked under arm, and Stan, whose face is apologetic and who is trudging along behind Mabel. The two of them stop and stare at the blond, and then Bill sticks his hand out in Mabel’s direction and introduces himself as Bill Cipher. She recoils in horror immediately, hiding behind Grunkle Stan, who - having been warned about the demon already by his brother - is already in the process of rushing to come in between him and his nephew. It’s only Dipper who feels differently. Instead of focusing on his hatred of Bill Cipher and all that he represents, he’s thinking only of what Bill said to him last - that he knew before of his illness. That’s more important to him now than the feud between his family and Bill. So is his claim that Ford is the one who injured him.

Without a word, Stan grabs the two children by their hands and drags them off down the hallway, speeding up with every stride and not stopping until they’ve reached the car. And yet somehow Bill still manages to beat them to it. He’s already sitting in the backseat on the right hand side, his long legs shoved under the passenger seat. Dipper slides in beside him, insisting that he tells him what he’s doing there. He doesn’t care that he should be afraid. As far as he’s concerned, the hospital is Hell and he’s just managed to escape.

Bill’s trademark grin returns to his face and Dipper is so busy staring at him that he barely notices the car start to move; in fact, he doesn’t even notice his sister climbing into the seat next to him or his uncle sitting in the driver’s seat. Before the demon opens his mouth to respond, Stan interrupts and demands to know when he’ll leave them alone.

“I’ll leave when I feel like it,” Bill mutters to Stan’s dismay. But then he says something that catches his attention. “And that won’t be until I’ve taught your brother a lesson. He needs to learn his place.” In spite of his intrigue, Stan holds back and refuses to say another word to the demon throughout the entire journey back to the Mystery Shack. 

During the ride, Mabel shoves the teddy bear into her brother’s arms and hands him the envelope, which he says he will open later. He doesn’t feel like being fussed over, though he is grateful. At some point, Bill ends up leaning against him, resting his head on his shoulder. It’s not that it doesn’t bother him; he just can’t find a reason to push him away, not when he looks so vulnerable even though his better judgement (and Mabel) is telling him otherwise, that even monsters can come across as angels sometimes. He feels the demon’s teeth nipping gently at his neck and clutches the teddy bear Mabel has given him tighter, running his fingers through the soft white fur and burying his face in it. Normally he hates teddy bears. But now his mind is crumbling and it feels like it’s all he’s got.

The car (dubbed El Diablo by Grunkle Stan) screeches to a halt outside the Mystery Shack and the doors fly open, Stan leading the way although Bill still manages to make it to the front of the Shack before anyone else. Wendy and Soos, oblivious as to the blond’s identity, rush to greet them and immediately bombard Dipper with questions the instant they reach him. Without answering any of them, Dipper pushes passed them and makes his way upstairs to the attic, tripping on the stairs as he so often does. Bill follows him blindly, his only aim being to stay as close to the brunet as possible.

Once he gets to the attic and throws himself on the bed, Dipper realises the demon’s presence and yells at him to go away - lifting his head up to glare at him momentarily - only to have a hand cover his mouth, silencing him. He’s shaking again. The teddy bear has fallen onto the floor beside his backpack and so has the envelope he’s been carrying around. The leaflet about his illness is still in his hands, the edges folded up slightly because he’s been gripping it too tightly. Bill moves his hand away from his mouth and sits down on the bed, slinging one arm around his shoulders. He doesn’t pull him any closer and Dipper doesn’t pull away.

“I’m going to die,” Dipper tells him, his voice dripping with hatred directed at no-one in particular. “I’m going to die,” he repeats. He hates Mabel for fussing over him. He hates Stan for not fussing over him. He hates Ford for not being there at the hospital with him. He hates himself for being weak enough to develop the illness in the first place, for not telling anyone about the seizures he’s been having for the past two years. And he hates Bill Cipher for knowing he was ill and not telling him - among other things.

“So is everyone,” Bill says flatly. “Well, not me of course. This body can die though, so I suppose that’s kind of the same thing.” Dipper glares up at him but keeps his mouth shut.  
They don’t speak for a few minutes until Bill suddenly pipes up again, breaking the awkward silence they’ve created between themselves. “I’m hungry, I think. Got anything to eat in here?”

Dipper rolls his eyes and shrugs the demon’s arm off him, kicking his legs out behind him as he lies down on his bed and stares up at the ceiling (well, he tries to, but Bill’s face blocks his view of it). “Kitchen,” he mutters, reaching out and pushing Bill’s head out of the way so he can get a better look at the dusty, cobweb-ridden ceiling. “Downstairs.” He waits for Bill to move but he doesn’t, so he sits up and snaps at him. “Go on then. You can go by yourself, can’t you?”

After a moment’s pause, the demon shakes his head. “I’m not leaving you alone.”

Dipper doesn’t know whether to be flattered or annoyed. He’s not feeling his best so he settles on annoyed and kicks the demon away. “Just get out! I don’t need you to babysit me.” When he lays back down and turns away to face the wall, he closes his eyes and pretends to falls asleep, but he should know better than to try and trick a dream demon when it comes to matters of slumber. Knowing he isn’t really asleep, Bill grabs his hand and stands up from the bed, dragging him down the stairs until they reach the kitchen. Dipper kicks out at him all the while but to no avail as the demon’s human body is much stronger than his own and besides, Bill has magic on his side.

With one arm wrapped around his waist, the demon marches into the kitchen and promptly begins rifling through every cupboard he sees, eventually turning to the fridge and taking out a can of cola which, after almost an entire minute of struggling to open, he finally thrusts into Dipper’s hands and commands him to open it for him. Dipper reluctantly does as he’s told. There can’t be any harm in opening a can of cola for him, can there? Then he stands back and watches as the demon pour half of the can’s contents directly onto his eye, yelping as at the stinging sensation it causes. Grabbing a cloth from a nearby counter and a straw from one of the kitchen drawers, he snatches the can off him and sets it down on the table, shoving the straw into it and mopping up the liquid from the demon’s face with a sigh. Bill is less than appreciative but smiles at him with almost genuine gratitude once Dipper hands him the can back and tells him to put the straw to his lips - not his eye - and suck.

Noticing that he’s stopped shaking, Dipper smiles back.

But then Ford walks in and everything’s ruined. Dipper’s heart is racing again because he’s going to have to tell Ford he’s dying. Because Bill and Ford are at war and all he wants is for them to stop getting at each other’s throats for a few minutes. Because Bill Cipher is for once not trying to wreck his life and Ford’s going to remind him how much they hate each other.

Ford glares at the demon as he walks in and snaps at him to get out and leave them alone, but suddenly Bill is back with an arm around Dipper again, crushing him to his side this time. “Pine Tree was just inviting me to stay, weren’t you, Pine Tree?” Dipper doesn’t know why he’s nodding but he is, even though his mind is screaming at him and his uncle is staring wide-eyed at him. “Come on, Six Fingers, this isn’t some game we’re playing. This is compensation. For an injury you caused.” He points to his forehead with his free hand and chuckles devilishly. “Pine Tree here is the only that feels any sympathy for me, isn’t that right?” Dipper nods again even though he has no idea what he’s agreeing to. He does, sort of, feel sorry for him - if he tries hard enough.

“Fine,” Ford growls through a set of gritted teeth. “But you’ll stay with me and leave him alone. Mabel and Stan too. You are not to go near them.” Dipper is surprised to hear Grunkle’s Stan’s name mentioned but doesn’t say anything, not wanting to destroy the compromise Ford and Bill seem to be on their way to making.

At least, Ford seems to be willing to compromise (probably because he has no choice and recognises that the demon is far more powerful than him). Bill, on the other hand, is a lot more stubborn than he is. “Shooting Star? Alright. Your brother? Not a problem. Pine Tree, however, is sticking with me. It’s what we both want.” 

This time Dipper manages to stop himself from nodding dumbly the second Bill stops speaking. His gaze flickers between the two of them, eventually settling on the blond. “You can stay with me. I don’t mind.” It’s an obvious lie but Bill accepts it as the truth anyway and holds out his hand, the all too familiar blue flame dancing in his palm as it always does when he’s about to make a deal.

“Come on kid. You know you want to,” he sighs when Dipper makes no move to shake his hand. Before he knows what’s doing, Dipper’s hand is in his and the demon interlocks their fingers. Ford is protesting, trying to stop him from making what he is calling the biggest mistake of his life (which only reminds Dipper that his life is going to be an incredibly short one in comparison to everyone else’s). But they’re shaking hands and then the blue flame extinguishes itself, signifying that the deal has been made. Dipper tries to pull his hand away but Bill grabs hold of his wrist, refusing to let go of him. Eventually, Dipper relaxes and even finds comfort in the warmth radiating from the demon’s body.

Ford looks dejected but reluctantly accepts that the deal has been made and there’s nothing he can do about it. At least Stan and Mabel are safe, he tells himself, if he sticks to the deal. Sending a glare in the demon’s direction, he turns back to his nephew and changes the subject. “Stan told me what happened at the hospital,” he starts in a sympathetic tone.

But Dipper doesn’t stick around to hear any more of what he’s got to say. He’s up the stairs, tripping over his feet again, before Ford can even open his mouth again. Bill tuts at him disapprovingly and follows Dipper upstairs, chasing after him and eventually finding him splayed out face-down on his bed, quietly sobbing into his pillow.

Being at the hospital was bad enough, but now he has to be interrogated in the place he’s starting to call his home when all he wants is to be treated normally. The phrase “out of the pan and into the fire” comes to mind. It feels as if he’s escaped one Hell and stepped right into another.


	2. No Control

While he’s lying on his bed, face down as his tears soak into his pillow, Dipper has no idea there’s a demon behind him, watching him, until he suddenly - literally - grabs his attention by reaching out and taking hold of the back of his shirt. His yelp of surprise is muffled by the pillow but Bill still hears it and lets go of his shirt immediately, grabbing his hand instead and shushing him. Turning over to lay on his back, Dipper shrugs him off and rips his hand away, wiping it on the mattress as if he can’t bear to let the demon touch him. He almost apologises when he catches sight of the confused, almost hurt look on Bill’s face, but then he remembers what he’s done to him and the rest of his family in the past and rolls away, facing the wall.

He expects Bill to leave him now, to get bored with him and walk away, probably to taunt Ford with the fact that he couldn’t stop his nephew from making a deal with him, but he doesn’t. Instead, he pulls the blanket out from underneath him, climbs into the bed and drags it over both them. He says something about the warmth being new to him but Dipper doesn’t hear him over the sound of his heartbeat and then his thoughts screaming at him, reminding him that the blond boy he’s lying next to is a demonic beast who has ruined his life on more than one occasion. That’s why he shuffles away from him and, after a moment, kicks back the blanket - earning an annoyed whine from the demon - and walks out of the room, drying his eyes on the way downstairs.

Bill sits up and stares at him, pulling the blanket back over him while he watches the brunet walk away, and then he chases after him again, catching up with him at the entrance to the living room and wrapping his arms around his waist as he stood behind him. Sending an angry glance his way, Dipper elbowed him in the stomach, causing him to loosen his grip enough for the human to release himself from his prison and take a seat on the floor by Grunkle Stan’s feet. He swears Bill grits his teeth as he walks away.

But then Bill’s next to him again, sitting on the floor beside him and they both glance at each other before their eyes are glued to the television screen. “Are you still here?” Stan grunts as he kicks the blond’s back with his foot. Bill mutters are sarcastic reply but doesn’t tear his gaze away from the screen until Stan leaves the room and he and Dipper are alone again.

“Aren’t you bored by this?” he asks, drawing Dipper’s attention away from the television for a few seconds.

Dipper shakes his head and then pauses because he’s not sure how to answer. “Bored by this,” he says involuntarily, looking up at the demon again. He hasn’t really been concentrating on the show; he doesn’t even know what it’s about. But the colours and motion are captivating and all he really wants right now is a distraction from his problems.

It’s obvious that Bill knows this - probably through reading his mind - because he suddenly replies to him without him having spoken out loud. “Then let me be your distraction.” Dipper’s eyes flicker over to him when he says that, his gaze laced with scepticism. Whatever Bill intends to do to “distract” him from his problems, he’s certain he wants no part in it. “Come on, Pine Tree. I’ll distract you from... you know, your illness in a much more exciting way than that thing ever will.” He gestures at the TV as he speaks and before he knows it Dipper is reaching for the remote and switching it off.

Bill disappears into the kitchen and Dipper waits patiently for him in the living room, sitting with his legs stretched out in front of him and - regardless of what the rational part of his mind is yelling at him - he actually starts to look forward to finding out what the demon has planned. If he knows one thing about Bill, it’s that life with him around certainly isn’t going to be boring. And maybe that’s just what he needs right now - excitement while he still has the chance to enjoy it.

After a couple of minutes (during which he hears more drawers and cupboards being opened and slammed shut as the demon clearly searches for something in particular) Bill eventually pokes his head round the door, peering in at him, and then steps back into the living room with his hands behind his back, hiding something from the human’s view. Then, as he sits down on the floor again, facing him, he produces a bottle of something from behind his back.

“I hear humans tend to enjoy this stuff,” he grins, unscrewing the lid and sniffing it before lapping up the strong-smelling residue that had somehow attached itself to the lid. The look on Dipper’s face suggests that he isn’t impressed with his idea of a distraction, and it only worsens when he holds the bottle up to his lips and pours the burning liquid down his throat. After a couple of mouthfuls, he wipes the back of his hand across his mouth and the grins returns. Then he shoves the bottle into Dipper’s trembling hands and orders him to drink.

Dipper stares at the bottle in his hands, the glass cool against his hot skin, and shakes his head. “Drink,” he repeats, almost like a question and Bill nods, not understanding that he was speaking involuntarily. “I can’t. I’m not old enough.” His voice is meek and he barely sounds like he believes what he’s saying himself, but Bill snatches the bottle from him anyway and gulps another few mouthfuls down without a word.

“Suit yourself,” he shrugs, pausing to allow himself to get acquainted with the new, foreign sensation the alcohol was causing his new, human body to feel. His body is starting to tingle and his throat feels as if it has been set alight, but the pain only encourages him to drink more.

By this point Dipper is starting to feel even more uncomfortable around him than he usually does and not just because he hates witnessing the drunken antics of adults (such as the few times he’s caught his parents drinking and the one time he’s seen Grunkle Stan after a few bottles of beer), but also because of the looks Bill is giving him now. He’s wearing a different smirk to the one he normally wears - not a knowing smirk, but a more… seductive smirk, like he’s starving and Dipper’s the only thing that can satisfy his hunger. “You shouldn’t be drinking that,” Dipper warns, partly out of concern for Bill but mainly because he’s afraid of what will happen if the demon continues to lose control of him. He shuffles backwards, moving away from him, but Bill crawls closer to him, setting the almost-empty bottle down on the floor.

“I may have the body of a human teenager,” he growls, his hand grazing the inside of Dipper’s leg and Dipper mentally corrects him, adding that he does in fact have the body of not just a teenager, but a drunken teenager. “But I’m still a demon, kid.” Dipper has no idea where he was going with this and decides that he probably doesn’t want to find out, so he swats his hand away from his leg and kneels instead, but this backfires on him and he ends up even closer to the demon than he’s expecting to be, their noses almost touching.

His breath smells of alcohol and it feels like just breathing it in is enough to get him drunk. He’s half-hoping someone - Ford, Stan, Mabel, anyone - will walk in and interrupt them but nobody does and suddenly Bill’s lips are crashing into his, his tongue forcing its way into his mouth and intoxicating him. His eyes close instinctively and he automatically lets out a soft, quiet moan when he feels the demon’s tongue pushing down against his own. Before he realises what’s happening his fingers are entangling themselves in Bill’s hair, tugging at the strands as he leans back and pulls him closer until eventually he’s lying on the floor with the demon on top of him.

It’s as if he’s lost control of his own body and he jerks his hips upwards, craving the friction that only Bill can provide him with. Frustratingly, that’s when Bill decides to stop. He pulls away, eliciting a whimper from the brunet, but stays straddling him. “Easy, kid. I thought you were the one complaining about being too young to have any fun… and now look at you,” his words are slurred but only slightly, and it makes Dipper wonder how much control the demon really has over himself in his current state.

But then his lips latch onto Dipper’s neck and this time Dipper’s the one who pushes him away, common sense taking over and telling him they have to stop before they surrender their control completely and go too far. “We can’t,” he protests and now Bill’s the one whining, pining for attention and yelping like a kicked puppy. At the time, Dipper wants nothing but to give in but manages to stay strong. Noticing the time, he uses the excuse that he’s tired and needs to go to sleep. At first, Bill says he’ll come up with him but then he doesn’t, suddenly changing his mind and telling him he’s going for a walk and that he wants to explore the town, but that he’ll be back soon.

Dipper doesn’t get much sleep that night and stays awake for hours after he goes to bed, but he doesn’t see Bill again until the following morning.


	3. Wish

It’s hours before Bill gets back from his alleged “walk.” When he finally does return Dipper and Mabel are both gathered round the kitchen table, eating their breakfast and the blonde suddenly comes blundering in, interrupting their meal as he grabs for Dipper’s shoulder and leans against him. His breathing is heavy and he can barely hold himself upright. Dipper’s initial reaction is concern - for both the demon and those around him - but then the memory of kissing him drags itself out from the back of his mind and he glances down at the floor, doing his best to ignore the demon’s presence. His nails are digging into his shoulder and he has to bite down on his lip to stop himself from crying out in pain.

It takes him a short while to notice that both his sister and Bill are speaking to him. Mabel is asking if he’s going to reply and Bill… Bill’s not making any sense. He sounds distressed, that’s for certain, but Dipper can’t understand why. He’s barely speaking and what he is saying is difficult to hear clearly, his words coming out strangulated and incoherent. Finally deciding he can’t ignore the blond any longer, Dipper stands up from his seat and pulls him out the room and into the hallway, leaving his half-eaten bowl of cereal lying unfinished on the table. Depending on how long this takes, Stan will probably finish it by the time he gets back to the kitchen.

“What do you want?” he hisses, ending up sounding more venomous than he’d meant to. Bill has his back pressed up against the wall but even in his vulnerable state, he still manages to switch their positions and pins Dipper against the door, using his arms to create a makeshift prison. “And where the hell were you last night?” Dipper growls, his hands balling into fists, and he realises he sounds too concerned about the demon’s welfare for his liking. “Not that I care,” he adds casually, hoping to deter the blond’s attention away from the worry in his voice.

Still breathing heavily, Bill slumps over, resting his forehead against Dipper’s and unintentionally pinning him against the door with even more force than before. “This body… feels…” he groans and cuts himself off mid-sentence, the eyelids around his visible golden eye closing automatically. He isn’t asleep, just… nearly. On the brink of unconsciousness. “What is this?” he yawns, words muffled by the fabric of Dipper’s shirt as he slumps further, pressing his face against the brunet’s chest.

Dipper can’t take any more. It’s bad enough not understanding why the demon is so distressed or why his eye keeps twitching while he speaks, but what’s worse is the embarrassment that comes with the memory of their hungry, lust-driven kisses becoming imprinted on his mind. Giving the blond a firm shove to the chest, he pushes him away but then quickly moves his hands to take hold of his shoulders as he realises Bill no longer has the strength to hold himself up.

“You’re just tired,” he sighs, stepping away from the door and letting go of the blond with one hand. “If you were really in that hospital for days, then you must have been asleep before.”

Lifting his head up to look at him, Bill frowned and just about managed to choke out a stifled response. “It’s never been this bad,” he mumbles, and then adds “I stayed awake all night,” as a slight explanation for his exhaustion. He lets the younger drag him upstairs willingly, though he doesn’t seem at all grateful for his help getting up the stairs (which he wouldn’t be able to do on his own, what with his extreme tiredness and the fact that he is still struggling to get used to his physical form).

Once upstairs, Bill curls up on Dipper’s bed while the brunet drapes his blanket over him, feeling uneasy about leaving the demon alone while he sleeps. Something else is bothering him and the blond has noticed and is smirking at him knowingly. Dipper doesn’t notice. He’s lost in his own thoughts, remembering their kiss for the nth time since it happened. He wonders where the demon had planned on sleeping in the first place, when he decided to stay with them, and if he’d always planned on sleeping in his bed. What about when they both sleep at the same time? Would Bill insist on sharing a bed with him? Probably, but how would he react if he refused to let him?

Finally, after the demon has closed his visible eye and has presumably gone to sleep, Dipper turns and staggers back downstairs to finish his breakfast. To his surprise, Mabel is the one finishing his breakfast for him and - shocked that he hasn’t seen Stan yet - he asks where their uncle is. He has to ask a few times because Mabel can’t hear him over the crunching of her - more specifically, his - cereal.

“Not here. Police. Gone for questioning,” she says between bites, failing to notice her brother’s eyes widen. “Don’t worry,” she assures him after a moment after she sees the look of horror in his eyes. “I don’t think he did anything wrong. He’s being questioned as a witness - he wasn’t arrested - and besides, I trust Grunkle Stan.” A chair screeches across the floor as Dipper pulls it out from under the kitchen table and sits down opposite his twin sister, resting his arms on the table as he listens to what she’s saying. “So what did the triangle guy want?” she asks, suddenly abandoning their current topic of conversation.

Dipper sighs at the mention of the demon. He’s been hoping to ignore the fact that he’s staying with them at least until he wakes up again. “Nothing. He was just tired and probably didn’t understand that’s what it was. He’s asleep now though,” he pauses, gritting his teeth in preparation for what he’s about to say. “In my bed.” Mabel evidently finds the idea of the blond sleeping in her brother’s bed a lot funnier than he does but he interrupts her laughter abruptly, asking more about their uncle Stan. “So what’s he apparently a witness to? Nothing too bad, right? Wait,” he muses just as his sister is about to answer. “Bill was out all last night. You don’t think that maybe… maybe he had something to do with it?”

Mabel simply shrugs. “I don’t know. You’re the detective. And I don’t know what he’s being questioned about either, just that they’ve taken him to the station to ask about something he saw.”

By this point, Dipper is already too caught up in his own thoughts to hear any of what she’s telling him. It had been suspicious when Bill left suddenly the night before, deciding to go for a walk without any prior warning, and now it was even more suspicious. Bill Cipher certainly doesn’t seem the type to commit petty theft or minor crimes, he tells himself, so it must be something more serious. Maybe even murder. Actually, probably murder. Demons are killers - he has no doubt about that - and Bill Cipher is the worst type of demon he can imagine existing.

He doesn’t learn that an unnatural death has actually taken place until a few hours later, when Stan still isn’t back and Ford comes up from the basement to make sure the two twelve year olds are coping without him, especially while Bill is hanging around them - though he seems a lot more interested in Dipper than he is in Mabel, and with Dipper having recently been diagnosed with a fatal illness, Ford can’t help but worry that he’s being exploited by the demon.

Bill is still asleep in the attic by this point, which Ford learns from his nephew when he finds them sitting on the floor in the living room, chatting amongst themselves. “You’ve heard about my brother, I presume,” he says to Dipper, glancing at Mabel as he speaks, recognising as his nephew nods in agreement that she’s the one who must have told him about Stan being questioned by the police. “You’re not worried?” Mabel shakes her head immediately but Dipper hesitates, wondering whether he should be worried about his uncle or not. He knows Stan has committed crimes in the past but this time, it seems more likely for Bill to be the culprit.

“I wouldn’t normally say this,” Ford continues, drawing his nephew’s attention, as he realises Dipper is thinking hard about his answer to his question. “But I think he’s innocent. Right now, my money’s on Cipher. It’s just too much of a coincidence that someone gets killed the first night that demon stays with us.”

“Someone actually died?” Dipper blurts out on impulse, losing control of himself for a moment. Then his thoughts drift back to the demon, sleeping in his bed, and he shudders automatically as he’s hit with the sudden realisation that someone - or something - really capable of murder is so close to him, that they’re asleep in his bed as he’s thinking about it and that they’ve kissed… and that he wanted more. He could put it down to the heat of the moment making him lose control but he knows that isn’t the case, the very thought of the demon’s lips pushing against his own bringing back the taste of alcohol on the blond’s breath and causing his heart to race.

He looks away and focuses his gaze on the carpet, pressing two fingers against the side of his neck to feel his pulse. It’s quicker than it should be and he blames the demon entirely. Then he hears a name mentioned by Grunkle Ford and looks up at him again, his gaze questioning. Now that he knows who the victim is, he’s determined to interrogate Bill about his whereabouts last night - and the early hours of this morning, seeing as his walk had taken an unusually long time.

But just as he’s about to reach the stairs, Wendy walks into the Mystery Shack and distracts him, announcing that she thought she could take him and Mabel out for lunch. Ford returns to his work down in the basement at this point, saying he’ll be sure to keep checking on the demon while they’re out. With that sorted, Dipper agrees and he and Mabel march out the door with Wendy leading them. They don’t go to the diner like they usually do but instead to the waterfall (after which the quaint little town is named) where they sit on the grass and eat the sandwiches Wendy has brought with her.

He feels uneasy the entire time. He tries to relax but he just can’t - and not because he’s left Bill alone in his and Mabel’s room. Someone’s watching him. He knows it. He can feel someone’s gaze boring holes in the back of his head but every time he turns around they seem to vanish into thin air. That’s until they start walking back to the Mystery Shack.

Seven and a half minutes into their journey Dipper hears a noise and whirls round, determined to catch whoever is watching him in the act. And then he does, though the person he finds staring back at him is usually more likely to be following Mabel as opposed to him. Gideon Gleeful. Mabel’s personal stalker and sworn enemy of Grunkle Stan. He tugs on his sister’s sleeve and points in the direction he swears he saw Gideon standing in, but when he swivels round again he finds that he’d disappeared, just like he seemed to be doing before.

A shiver runs down his spine but he carries on walking, turning his attention to the interrogation he’s going to make Bill suffer through.

Bill is awake by the time he gets back. The first thing he does is run up to the attic without a word - leaving Wendy and his sister to stare after him - where he finds the blond sitting upright in his bed, the blanket still covering him. “I was wondering when you’d be getting back,” the demon grins, clearly having gotten his usual devilish demeanour back.  
Dipper scowls at him as he crossed the floor and perches on the edge of his bed. “I need to talk to you,” he grumbles, glaring at the grinning demon coldly.

“About that woman who died, I know,” the blond interrupts him, prompting the younger’s glare to intensify. “Let’s make a deal, kid. You do something for me and I’ll grant you a wish. Anything at all… Money, information… Or, I could make that disease of yours disappear.” The mention of his illness grabs Dipper’s attention and his eyes widen, his icy glare melting away into an intrigued gaze. Without his illness, he’d have his life back. People would treat him normally again. But the other thing he wouldn’t be opposed to wishing for is the demon leaving him alone - leaving his entire family alone, forever.

Before he knows it, Bill’s left hand is outstretched, a familiar blue flame hovering above his palm. Dipper hesitates, reluctant to make another deal with him considering how things turned out the first time he made that mistake. But he could have anything he wanted. Freedom, a long healthy life without sickness, a life without Bill. Or Wendy.

He’s decided he’ll do it, momentarily forgetting that the demon’s deals are almost certainly always designed in his own favour and that he’ll have to do something for him in order for his wish to be granted. But by the time he realises that he’s already shaking the blond’s hand, their fingers intertwined. How bad can it be? He made another deal with him yesterday and it hasn’t worked out too badly for him yet, though it’s possible (and likely) that someone has died because of it. There’s no definitive proof of that yet though.

“I think you know what I want from you, Pine Tree.” The demon’s voice suddenly tears through their silence and he instinctively tries to rip his hand away, only for the blond to tighten his grip on him and pull him closer, his trademark smirk returning to his face as his golden eye glimmers with hellish intent. “And this will be good for both of us, not just me. Really, it’s like you’re getting two wishes.” Dipper can do nothing but frown at him in response, confused; he really doesn’t know what he wants from him.

Then he figures it out. This is mainly because Bill’s lips are devouring his own again, just as they were last night, but this time Dipper tries to pull away from him before he can make any more mistakes and fails, the demon trapping him against the wall beside the bed and wrapping his arms around his waist, preventing him from escaping. He feels a sharp stabbing pain in his lower lip as Bill’s teeth tear into it, making him gasp and then wince as the metallic taste of blood fill his mouth. There’s suddenly a hand on his chest, wandering down until it reaches the waistband of his shorts and he uses as much strength as he can muster to shove the demon away.

“We have a deal, remember, kid? You can’t back out now,” Bill smirks, leaning towards him again. He’s kneeling now and he quickly pushes the brunet back into the position they were in before, his hand returning to the front of his shorts. His lips latch onto Dipper’s to keep him quiet as his fingers dip below the waistband of his shorts, a gasp escaping the younger’s lips when his fingertips ghost over the bulge that is now starting to form between his thighs.

Recognising his feelings as something he doesn’t want to share with the demon, Dipper thrashes around and manages to get away from his grasp, standing up from the bed with the intention of running back downstairs where he’d be in the company of others who’d be able to protect him if necessary. But he never touches the first step. Bill takes hold of him from behind, his arms snaking around the younger’s waist, this time in a gentler manner.

Acting on instinct, Dipper uses one arm to shove him away and the other to keep one of his arms in place, stopping him from grabbing at him again as he turns round to face him. “You have to stop, please,” he whimpers, detesting the way he sounds so weak. His eyes are already watery and he feels he could break down sobbing at any moment.

“Why?” is the only response he gets from the demon but Bill leaves him alone after that. “Just think about it,” the blond urges him later on, after Dipper has calmed down from the attack. He nods and says that he will, although he has no intention whatsoever of ever letting the demon touch him again.

When Stan finally returns, Dipper has fallen into a deep silence he doesn’t know that he’ll come back from.


	4. Darkest Side

It’s days later and Dipper still hasn’t spoken a word. Bill has been following him around, keeping his distance but it’s still obvious to everyone else that he’s unwilling to leave Dipper alone. So far, Grunkle Stan has been released from his confinements at the police station and has been allowed to come home, though his likely involvement in the suspicious death that has recently taken place has not been forgotten by the police or by his family members. In Dipper’s mind, while the fact that he is a known criminal is too difficult to ignore in this situation, the demon must have also gotten himself involved in the murder. He has to have been.

Last night, the warmth that usually accompanied him as he slipped into bed was missing. Bill had chosen to sleep on the floor instead, for whatever reason, and, thinking about it as he curls up on the floor in front of the television set, Dipper knows he should be glad about it. But instead he finds himself wondering why the blond didn’t want to sleep next to him in his bed anymore and why then a thought suddenly erupts inside his brain: why does he care so much? It’s not of his concern where the demon chooses to sleep, but he still can’t help feeling rejected. The few nights they slept side by side were the most peaceful nights he can remember experiencing - no more bad dreams, no more waking up in the middle of the night with a cold sweat.

He smiles to himself as he recognises the irony of sleeping peacefully next to a dream demon hell bent on creating chaos, prompting Mabel to point out that he hasn’t seemed this happy in a while. He doesn’t reply. He never replies - not since Bill tried to coerce him into a physical relationship a few days earlier. Nobody knows whether he’d ever speak again and no-one aside from him and Bill knows why, though his response has undoubtedly confused the demon even more than he realises.

The television screen Dipper’s gaze is fixed on suddenly turns from colour and motion that has him hypnotised to unbearable static and he snaps out of his trance, scowling across at Mabel as she hovers over him with the remote in her hand. She’s done this to elicit a response from him and he knows it. It doesn’t work. He doesn’t feel like talking and he doesn’t think he ever will. Ever since he found out about his inevitably fatal illness everything has gone downhill for him. There doesn’t seem much point in talking anymore. There doesn’t seem much point in anything.

So instead of answering her when she asks him what he was smiling about, he stands up and strides past her, heading in the direction of the front door and glancing at the blond - who has been watching from the doorway - as he passes him, only to walk straight into Stan. Mabel was about to follow him but stopped when she saw Stan - something that Dipper should have done. Bill, on the other hand, grins at the notion that the younger boy has been stopped in his tracks and moves to stand by his side, so close that their hands are almost touching as they hang loose at their sides. Stan glares down at him and he simply grins back, cheerfully awaiting what the man has to say to them both.

“You two. In the Gift Shop. Now!” It’s clear to the both of them that it’s not a request but a command and Dipper obediently turns on his heel and begins walking in the opposite direction immediately. He can feel the blond’s gaze boring holes into the back of his skull and silently prays he won’t be followed. His prayers aren’t answered, or if they are they’re only answered with a slap in the face because Bill’s footsteps soon begin to echo off the wooden floorboards beneath them as they both make their way to the gift shop. “You as well, Mabel,” they hear Stan shout from behind them and she’s suddenly scuttling past them in the hallway, trying to be the first one to reach their destination.

Bill mumbles something under his breath as he catches up to Dipper but the younger boy doesn’t hear him, too caught up in his own sordid thoughts to notice. He’s still stuck on whether the deal they’d made promising him a single wish that would grant him anything he wanted - to rid himself of his fatal disease, for example - was still in progress, considering that he’d turned down the demon’s sexual advances after they’d shaken hands. The blond steps in front of him, blocking his path, and smirks, presumably reading his mind. Dipper simply glances at him and pushes past, surprised at how easily he shoves the demon aside.

The gift shop is virtually empty when they get there. Wendy is half out the door, her friends waiting for her outside. Mabel is talking to one of the customers (and there aren’t very many) in attempt to convince them to buy something even though the look on the customer’s face clearly suggests they’d rather be anywhere but there. Dipper takes his seat at the cash register and fakes a smile. He’s been doing that a lot over the past few days. Still insisting they stayed close together, Bill walks over and stands next to him, eyeing the customers suspiciously.

“Dipper!” Mabel hisses after the woman she was talking to leaves without purchasing anything. “You won’t sell anything if you don’t talk to anyone!” Then her gaze flickers over to the blond and an idea strikes her. “Let Bill handle it.” She frowns as soon as the words leave her mouth and Dipper looks away from her, his gaze meeting with the demon’s. “Grunkle Stan will be really mad if we don’t make any money, and you’re not gonna sell anything like that. Him, on the other hand” - she jerked a thumb in the blond’s direction - “He’ll be a bit more talkative… and forceful.”

Keeping his gaze trained on Dipper’s face, Bill grins a wide, proud grin and suddenly proclaims that he’ll make as much money as he can if it means Dipper can have a rest. Dipper scowls at him but allows the demon to take his place at the cash register and takes a step back, watching him. Amazingly, his first conversation with a customer goes surprisingly well. He’s assertive but not it’s not too obvious that he’s trying to persuade the man to buy anything and he somehow manages to make the numerous purchases the one customer makes appear to be the customer’s own idea.

But, as with everything involving Bill Cipher, it can only end in disaster.

It does, at least, encourage Dipper to start speaking again.

As soon as the demon’s jaw clamps shut around the wrist of the woman he’s trying to convince to buy one of the gift shop’s t-shirts, the illusion of grace and diplomacy the blond has built up shatters and Dipper immediately steps in - even beating Mabel to it. He claws at Bill’s hand and tears him away from the customer, a sudden surge of strength guiding him as he drags him back out into the corridor.

“What on earth made you think it was okay to do that?” he snaps, his hand still firmly wrapped around the blond’s wrist. Bill looks back at him with alarm in his single golden eye but he doesn’t move away, holding the younger boy’s gaze with confidence as though he’s done nothing wrong. “You can’t go around biting people!” Dipper exclaims in a paroxysm of frustration, unable to comprehend the reason behind the demon’s unfathomable behaviour.

Bill simply smirks at him, the apprehension having now drained from his face and been replaced with a familiar air of arrogance. “Like you’d mind if I bit you.” It’s not a joke - or at least it doesn’t sound like one - and Dipper doesn’t find it very funny if it is. Letting go of the demon, he folds his arms across his chest and sulks, only making the blond laugh at his childish appearance. “So you’re finally speaking again. Good. I’ve missed talking to you.”

The expression on Dipper’s face doesn’t change and he remains silent, unable to decide between acting like he doesn’t care or telling him the truth - that he’s confused about their relationship and needs to know how he feels. He is thinking about answering but Stan bursts through the door and interrupts, whether he’s planning on reply or not. Mabel has told him what Bill has done (naturally) and this is immediately clear to the both of them simply judging by the expression on his face as he approaches them. In a fit of anger, frustration and despair, he orders the demon to leave without giving either of them a chance to speak.

But while Bill makes it abundantly clear from the look he gives Grunkle Stan that he has no intention of leaving, Dipper is determined that he’ll do as Stan tells him; Bill deserves it after all, now that he’s bitten an innocent customer. So before the demon can open his mouth and argue back, he suggests that they go somewhere else together for a while, knowing that Stan isn’t going to allow him to stay and that the blond isn’t going to leave for good. Grabbing his backpack on the way out, he leads the demon out the door and gives his uncle a look of sympathy as they leave. He hates seeing the people he cares about upset but at the same time, he can’t help but feel somewhat responsible for the demon’s actions.

Bill laughs at him as they walk through the door, apparently feeling like he’s accomplished something. Dipper stays quiet as he leads him into the forest he and Mabel have explored so often together. It feels strange without her but he presses on, the sound of the waterfall’s rushing water spurring him on. Bill tries to talk to him but he pretends not to hear, until he feels the demon’s arm snaking around his waist and he swats him away immediately, his nostalgic daydream splintering into a thousand frightfully realistic pieces.

“What did you take me here to do, Pine Tree?” The blond narrows his eye at him in suspicion as they sit down on the grass beside the water. “It won’t work, you know. You can’t lose me this way. I’ll find you. I’ll always find you.” Dipper glances up at him momentarily, crossing his legs as he opens up his backpack without looking at it, and then turns his attention to the book in his hands without replying. Bill sighs in response and splays out on the grass with a bored groan. “I want to do something!” he practically yells, snatching up a nearby stone and hurling it into the water. It hits the surface with a splash, instantly becoming submerged.

Dipper succeeds in ignoring him, immersed in the mystery novel he is currently reading, until the demon sidles up to him and jabs him in the ribs, knocking him over and prising the book out of his hands. Crying out in both pain and shock, Dipper scrambles back into a more comfortable sitting position and is about to snatch the book back from the blond when he notices the look of confusion on the demon’s face. He can’t seem to understand any of it. Dipper sits there staring until Bill eventually snaps at him to stop.

“Can I have my book back then?” Dipper asks hesitantly, his voice faltering. They haven’t been alone together since he turned down the blond’s sexual advances and doesn’t want to do or say anything that might remind him of what had happened between them, in case he tries to force himself on him again. He holds his hand out with a tentative expectance and the demon snorts in derision at him but passed the book back to him anyway. “Thank you,” Dipper mutters somewhat grudgingly.

“It doesn’t make any sense anyway,” Bill mumbles back in reply. At this point, Dipper is under the assumption that he’s referring to the plot of the novel which even he has to admit is somewhat far-fetched and unrealistic despite the things both of them have seen. But then, when the blond suddenly (and not to mention rather reluctantly) tells him that it’s all written in a language he doesn’t understand even though he’s certain he can understand every language in existence, the reality dawns on him and he can’t help feeling proud that he is able to do something the demon can’t.

“Are you trying to tell me,” Dipper starts, closing the book and dropping it down on the grass beside him. “That you can’t read?” 

The blond scoffs at him in reaction, initially refusing to admit it. “Don’t be ridiculous, Pine Tree. I have no weaknesses!” He pauses, giving Dipper the time to sigh and roll his eyes at him. “Well, if I do, it’s all Six Fingers’ fault. He’s the one that hit me.” Dipper doesn’t even bother looking at him when he gestures to his head, where his uncle supposedly injured him, and instead tries to drown out his voice entirely with his own thoughts.

“Everyone has weaknesses, Bill,” he says after a few moments of silence.

“And everyone has a dark side, kid,” the blond retorts. “But you don’t want to admit that, do you?”


End file.
